Ho Chi Minh City and southern provinces are battling an unseasonal spread of dengue fever, with thousands of cases reported including three deaths last month.

Statistics from the Ministry of Health showed that the country has recorded more than 5,200 infections so far this year, including 3,640 infections in February, mostly in the south.

The three dead patients were from Dong Nai and Long An, both neighboring HCMC.

There have been 27 percent more cases compared to the same period last year, when there was only one dead patient.

Dengue fever is a tropical disease spread by mosquitoes, with symptoms including high fever and joint pain. According to the World Health Organization, severe cases need to be treated as soon as possible to avoid lethal complications.

Dr. Phan Trong Lan, head of the Pasteur Institute in Ho Chi Minh City, said the beginning of the year used to be the low season of dengue fever.

But experts have detected high concentration of the virus since late last year in HCMC and nearby provinces.

Doctors at HCMC Children’s Hospital No.1 just saved a 7-year-old boy from Long An who suffered respiration failure and liver damage after having high fever for three days.

They had to put him on a respirator and provided blood transfusion for more than a week.

Doctors said parents should watch out for abnormal conditions at their children to send them to hospital early.